The present invention relates to a braking arrangement. The invention also relates to an attachment member and a corresponding method for interconnecting a brake liner to a backing plate by means of the attachment member. The invention is applicable on vehicles, in particularly heavy duty vehicle such as e.g. trucks or buses. However, although the invention will mainly be described in relation to a truck, the invention is of course also applicable for other type of vehicles using drum brakes, such as e.g. cars or working machines, etc.
In connection to the field of braking arrangements for vehicles, an often used braking arrangement is a drum brake. When the drum brake is activated, i.e. when the vehicle is braking, a brake liner of the drum brake is forced in a radially outward direction of the drum brake where it is abutting a friction material of the vehicle wheel, which thus reduces the speed of the vehicle. Hence, the brake liner of the drum brake is a wearing part which has to be replaced within predetermined time intervals.
The brake liner is often connectable to a backing plate of the drum brake. The interconnection between the brake liner and the backing plate can be made in a number of different fashions. A relatively normal procedure is to interconnect the brake liner to the backing plate by means of a rivet or the like such that a tight and secure fit between the two parts are achieved.
US 2002/0121412 describes a braking arrangement comprising brake lining segments which are connectable to a brake shoe of a drum brake by means of keying element. The braking arrangement in US 2002/0121412 strives to improve the interconnection between the brake lining segments and the brake shoe such as to prevent detachment of the lining segments from the brake shoe during use.
However, the braking arrangement in US 2002/0121412 is still in need of further improvements in terms of e.g. simplified service procedure when exchanging the brake lining segments.
It is desirable to provide a braking arrangement having a brake liner which is simpler to assemble to a backing plate in comparison to the prior art.
According to a first aspect of the invention, there is provided a braking arrangement comprising a brake liner, a backing plate and an attachment member for interconnecting the brake liner to the backing plate, wherein the brake liner comprises a recess in a surface facing the backing plate, wherein the backing plate comprises a through hole associated to the recess of the brake liner; wherein the attachment member comprises a first portion engaging the recess of the brake liner, wherein the attachment member further comprises a second portion extending from the first portion of the attachment member and forming a one-piece unit with the first portion, and wherein the second portion extends into the through hole of the backing plate and engages with the backing plate.
The wording “through hole associated to the recess” should in the following and throughout the entire description be interpreted as the through hole and the recess are arranged in connection to each other such that the attachment member can engage both the brake liner and the backing plate. The through hole can be arranged in alignment with the recess or it can be arranged slightly offset to the recess. Hence, the wording “through hole associated to the recess” should not be construed as limited to an arrangement where the through hole and the recess are arranged in absolute alignment with each other since certain tolerances may be considered acceptable.
Furthermore, the wording “forming a one-piece unit with the first portion” should in the following and throughout the entire description be interpreted as an attachment member where the first and second portions are integrally formed with each other, i.e. the first portion and the second portion are arranged as an integral part.
This braking arrangement creates conditions for a simplified assembly of the attachment member when interconnecting the brake liner to the backing plate, since the use of additional assembly components, such as e.g. screws or bolts, are no longer necessary. In more detail, the second portion of the attachment member is hence used as an attachment means for interconnecting the brake liner to the backing plate. A pressing machine or the like can be used when assembling the components such that a tight fit is achieved.
Advantages of the present invention is thus that a braking arrangement is provided which comprises fewer components in comparison to the prior art. Also, assembly of the braking arrangement is simplified and more time efficient since it does not require any attachment by means of screws or bolts, which attachment methods are time consuming and more difficult to automatize, since it requires a visual determination that the threaded holes of the attachment members are arranged in alignment with the holes of the backing plate. The present invention on the other hand merely needs to position the attachment member in the recess and the through hole; whereby the pressing machine can press the attachment member in place.
According to an example embodiment, the second portion may extend through the through hole of the backing plate and engage with a surface of the backing plate located on an opposite side of the backing plate in relation to the brake liner.
Hereby, the engagement between the second portion and the backing plate is further improved, i.e. the interconnection between the second portion of the attachment member and the surface of the backing plate provides for a connection to a well defined surface which connection further prevents the brake liner to be detached during use of the braking arrangement.
According to an example embodiment, the second portion may engage the surface of the backing plate on opposite sides of the through hole.
An advantage is that a more or less symmetric engagement of the attachment member is provided which efficiently distributes the upcoming force from the braking procedure.
According to an example embodiment, the second portion may comprise a pair of legs. The pair of legs is advantageous since they can be arranged on opposite sides of the above described through hole. Also, the pair of legs is advantageous during assembly, since a pressing machine, having a tapering end portion to press the second portion, will more or less automatically press the legs to opposite sides of the through hole.
According to an example embodiment, each of the legs of the second portion of the attachment member may comprise an end portion having a J-formed flange, wherein the J-formed flanges are facing away from each other.
Hereby, the J-formed flanges will provide for a circumferentially arranged force on the backing plate by means of the leg portion, as well as a support in the radial direction of the braking arrangement by means of the J-formed flanges.
According to an example embodiment, the recess may be elongated and extend in an axial direction of the brake liner from an axial end portion of the brake liner towards a center portion thereof. An advantage is that the braking arrangement is further improved in relation to an assembly perspective, whereby the attachment member can be provided to the brake liner and the backing plate from a side portion thereof and thereafter pressed to provide the final braking arrangement. Having access to the recess of the brake liner from an axial end portion of the braking arrangement is advantageous since the attachment member will be easily accessible during service of the braking arrangement.
According to an example embodiment, the brake liner may comprise a plurality of circumferentially spaced recesses. Hereby, the interconnection between the brake liner and the backing plate is further secured. According to an example embodiment, the backing plate may comprise a plurality of circumferentially spaced through holes associated to the recesses.
According to an example embodiment, the first portion of the attachment member may comprise a dovetail shaped portion. The dovetail shaped portion prevents the attachment member from moving in the radial direction of the braking arrangement.
According to an example embodiment, the recess of the brake liner may comprise a dovetail shaped portion. Hereby, the dimensions of the dovetail shaped portion of the attachment member may correspond to the dovetail shape of the recess for providing an improved fit there between. However, providing a dovetail shaped recess does not have to imply that also the first portion of the attachment member comprises a dovetailed shaped portion.
According to an example embodiment, the recess of the brake liner may be formed as a through hole having a protruding portion at a side of the brake liner facing the backing plate.
According to an example embodiment, the through hole may be positioned at a predetermined non-zero distance from an axial end portion of the brake liner.
According to a second aspect of the present invention, there is provided a braking arrangement comprising a brake liner, a backing plate and an attachment member for interconnecting the brake liner to the backing plate, wherein the brake liner comprises a recess in a surface facing the backing plate, wherein the backing plate comprises a through hole associated to the recess of the brake liner; wherein the attachment member comprises a first portion engaging the recess of the brake liner, wherein the attachment member further comprises a second portion extending from the first portion of the attachment member, wherein the second portion comprises a pair of legs extending into the through hole of the backing plate and engages with the backing plate.
An advantage of the second aspect of the present invention is that the attachment member can be made in a two-piece configuration, i.e. as two separate components which are interconnected to each other by means of a e.g. a screw, a bolt, etc. Hereby, the first portion can engage the recess of the brake liner and the second portion can engage the through hole, where after the first and second portions of the attachment members are interconnected to each other.
Further effects and features of this second aspect of the present invention are largely analogous to those described above in relation to the first aspect of the present invention.
According to a third aspect of the present invention, there is provided an attachment member configured to interconnect a brake liner to a backing plate, wherein the attachment member comprises a first portion configured to engage a recess of the brake liner, wherein the attachment member further comprises a second portion extending from the first portion and forming a one-piece unit with the first portion, wherein said second portion is configured to extend into a through hole of the backing plate and engage with the backing plate when the attachment member interconnects the brake liner to the backing plate.
Hereby, an attachment member is provided which is arranged in such a way as to provide for a simplified interconnection between the brake liner and the backing plate.
According to an example embodiment, the second portion may be configured to extend through the through hole of the backing plate and engage with a surface of the backing plate located on an opposite side of the backing plate in relation to the brake liner.
According to an example embodiment, the second portion may comprise a pair of legs.
According to an example embodiment, each of the legs of the second portion may be configured to be formed in a J-formed flange when the attachment member interconnects the brake liner to the backing plate, wherein the J-formed flanges are configured to face away from each other.
According to an example embodiment, the first portion may comprise a dovetail shaped portion.
According to an example embodiment, the first portion may comprise a protruding portion extending from outer end portions of the dovetail shaped portion towards a longitudinal center plane of the attachment member and in a direction away from the extension of the second portion.
An advantage is that the protruding portion may be designed such that it, when the brake liner interconnects with the backing plate, is arranged in abutment with an inner portion of the recess, providing a tight fit between the first portion of the attachment member and the recess of the brake liner.
According to an example embodiment, the second portion may be configured to be deformed from a first, non-operative state, to a second, operative state, in which the second portion engages with the backing plate. Hereby, the second portion is deformable such that the attachment member will engage with the backing plate.
According to an example embodiment, the legs may be arranged in a first mutual position in the first, non-operative state, and configured to be arranged in a second mutual position in the second, operative state, wherein the legs are configured to be arranged in a diverging mutual position in the second, operative state.
Further effects and features of the third aspect of the present invention are largely analogous to those described above in relation to the first and second aspects of the present invention.
According to a fourth aspect of the present invention, there is provided an attachment member configured to interconnect a brake liner to a backing plate, wherein the attachment member comprises a first portion configured to engage a recess of the brake liner, wherein the attachment member further comprises a second portion extending from the first portion, wherein the second portion comprises a pair of legs configured to extend into a through hole of the backing plate and engage with the backing plate when the attachment member interconnects the brake liner to the backing plate.
According to an example embodiment, the pair of legs may form a one-piece unit with the first portion.
Effects and features of the fourth aspect are largely analogous to those described above in relation to the first, second and third aspects of the present invention.
According to a fifth aspect of the present invention, there is provided a drum brake comprising a pair of brake shoes, which are movably arranged in relation to each other in a radial direction of the drum brake and a braking arrangement according to any one of the above described example embodiments, wherein the backing plate is attached to one of the brake shoes.
Effects and features of the fifth aspect of the present invention are largely analogous to those described above in relation to the first, second, third and fourth aspects of the present invention.
According to a sixth aspect of the present invention, there is provided a vehicle comprising a braking arrangement according to any one of the above described example embodiments in relation to the first aspect of the present invention, or a drum brake according to the above described fifth aspect of the present invention.
Effects and features of the sixth aspect of the present invention are largely analogous to those described above in relation to the first, second, third, fourth and fifth aspects of the present invention.
According to a seventh aspect of the present invention, there is provided a method for interconnecting a brake liner to a backing plate by means of an attachment member, the method comprising the steps of positioning the brake liner on an outer surface of the backing plate such that a recess of the brake liner is associated with a through hole of the backing plate; providing the attachment member to the brake liner and the backing plate such that a first portion of the attachment member is positioned in the recess of the brake liner and a second portion of the attachment member, extending from the first portion and forming a one-piece unit with the first portion, is positioned in the through hole of the backing plate; and pressing the second portion in a direction towards the brake liner for engaging the second portion with the backing plate.
Hereby, a method is provided which simplifies the interconnection between the brake liner and the backing plate. Hence, when the brake liner is worn out, switching to a new brake liner is made in a time efficient and secure manner. According to an example embodiment, the attachment member may be provided to the brake liner and thereafter provided to the backing plate.
According to an example embodiment, the step of providing the attachment member to the brake liner and the backing plate may be executed by means of directing the attachment member from an axial end portion of the backing plate towards a center portion thereof.
Further effects and features of the seventh aspect of the present invention are largely analogous to those described above in relation to the other aspects of the present invention.
Further features of, and advantages with, the present invention will become apparent when studying the appended claims and the following description. The skilled person realize that different features of the present invention may be combined to create embodiments other than those described in the following, without departing from the scope of the present invention.